When it's Hot, Check Your Lake Water for These 4 Things Before You Swim, Boat or Play

Canada is home to the most lakes in the world, and we’re lucky to have these pockets of cool refreshment on hot summer days. Whether you’re a veteran boater, novice swimmer, sand-castle-maker or hiker who sends their dog in to cool off, there are a few things you should know about lake water before ‘diving in’.

#1: Long, hot summer days make a perfect environment for certain organisms to flourish

It’s usually in August and September that we see a blue-green algae bloom or two in our area. Despite looking interesting—or even beautiful—these blooms of microscopic organisms can produce toxins that have the potential to make people and pets sick. It might smell like freshly mown grass or rotting garbage, and make the water look blue-green, olive-green or red. Blue-green algae requires special precautions.

#2: The weather influences bacteria levels

You can expect higher bacterial contamination after:

Heavy rain

Wind high enough to create waves big enough to stir up sand and silt

#3: Waterfowl make water foul

Ok, not just waterfowl. Any birds, including seagulls, geese and ducks and their droppings can up the bacteria levels in a lake. Dead fish, algae/scum and other debris can have the same effect.

#4: Some lakes are more susceptible to contamination than others

Busy, crowded beaches can lead to unhygienic conditions

Shallow water (including sand that stays wet) heats up faster and makes it more likely to grow bacteria

Lakes are natural bodies of water that support a variety of plants and animals – some harmless and others not. There is always a risk to swimming in a lake, river or stream

Whether you see visible signs of less-than-optimal water quality or not, it’s a good idea to take certain steps while swimming or using lake water:

Wash off after getting out of the water

Wash hands or use hand sanitizer after going in the water or playing in the sand (and especially before eating)